The House Committee on Oversight and Government Reform has launched an investigation into the White House’s handling of senior aide Rob Porter, who was not issued a permanent security clearance due to allegations of domestic abuse by his two ex-wives.

“Who knew what, when, and to what extent? Those are the questions that I think ought to be asked,” the committee’s chairman, Republican Rep. Trey Gowdy of South Carolina, said Wednesday on CNN.

“And if you knew it in 2017 — and the [FBI] briefed [White House officials] three times, then how in the hell was he still employed? ... How do you have any job if you have credible allegations of domestic abuse?”

“He also, as you probably know, says he’s innocent, and I think you have to remember that,” said the president, who has faced sexual assault accusations from multiple women. “He said very strongly yesterday that he’s innocent, so you have to talk to him about that. But we absolutely wish him well. He did a very good job when he was at the White House.”

Trump’s communications team has offered conflicting statements and timelines on the series of events within the White House dealing with Porter’s employment. Meanwhile, FBI Director Christopher Wray contradicted some of those accounts in testimony before the Senate Intelligence Committee on Tuesday.